The protector itself is machined from High Density Polyethylene (HDPE) – chosen because as it wears it actually helps to slow a sliding bike. The bolts used are also de-embrittled steel; working as a shock absorber to bend instead of snapping or staying rigid - which could twist the mounting point.

Cons:To keep these in the correct position while getting them tight can be a bit tricky. Need strong hands. Still a simple install. The end caps provided to snap in and a little loose fitting so I used electrical tape to seal the gap and prevent rattling/vibration, just a small annoyance. Still giving them a 5 star as these are such minor cons.